Nutrient composition and functional constituents of daylily from different producing areas based on widely targeted metabolomics

Daylily is a functional food with high nutritional value in China. Datong (DT) in Shanxi Province is one of the four main production areas of daylily. Therefore, Linfen (LF), Lvliang (LL), and Yangquan (YQ) in Shanxi Province have also introduced daylily from DT. However, geographical and climatic conditions and producing patterns cause variations in the daylily quality. In the present study, we found that the nutrient composition of daylilies from different producing areas of Shanxi Province varied. The key environmental factors affecting the nutrition of daylily in different regions were altitude and temperature. The widely targeted metabolomics results showed that 1642 metabolites were found in daylily. The differential metabolites between DT and YQ, LL and LF were 557, 667, and 359, respectively. Notably, 9 metabolic pathways and 59 metabolite markers were associated with daylily from different areas. This study provides a theoretical basis for the quality maintenance and health efficacy research of daylily.

Study on the material basis and mechanism of Hemerocallis citrina Baroni on sleep-improvement using Drosophila activity monitoring, metabolomic, targeted screening and transcriptomic

Daylily (Hemerocallis citrina Baroni, HC) is an edible plant and is traditionally considered with potential to improve sleep. Herein, based on the Drosophila activity monitoring, metabolome, targeted screening and transcriptome, the material basis and mechanism of HC on sleep-improvement was investigated. The results showed that the aqueous extracts of HC (HAE) as well as the ethanol extracts (HEE) all prolonged the total sleep time of insomnia fruit flies, especially HEE-60 and HEE-95 exhibited more significant effects. In addition, 539 of 728 found metabolites were screened as potential sleep-improved metabolites, and quercetin, linoleic acid, phenethyl caffeate, L-methionine and γ-aminobutyric acid were considered as core active metabolites. Meanwhile, 368 differentially expressed genes (DEGs) were revealed by transcriptomics analysis, and the neuroactive ligand-receptor interaction was deduced as the main pathway by KEGG pathway enrichment. Furthermore, nine DEGs located in this pathway, namely betaTry, deltaTry, gammaTry, epsilonTry, etaTry, iotaTry, lambdaTry, kappaTry and CG30031 were proven being up-regulated. All these results contribute to the development of HC-related functional foods.

First Report of Meloidogyne incognita on Daylily (Hemerocallis citrina) in Shaanxi, China

Daylilies (Hemerocallis citrina Baroni) are herbaceous perennials grown extensively as ornamental plants worldwide. In China, daylilies are important cash crops, which are used for their roots, leaves, and flowers as both food and medicine (Guo et al., 2022). Dali County, Shaanxi Province, is an important production region for the commercial cultivation of daylily in China. The daylily cultivation area of Dali County was 43.33 million m2 and the output reached 227 thousand kg, which worth more than 109.12 million dollars. In July 2021, numerous daylily plants (cv. Shayuan) showed chlorotic leaves and stunted growth in a field in Dali County. The area of daylily field we investigated was about 2000 m2, and the incidence of root-knot nematode disease was more than 90%. The inflorescences of diseased plants decreased by nearly 30%, which affected the yield seriously. The diseased plants exhibited obvious galling on the roots which were typical symptoms of infection by root-knot nematodes (RKNs). Population densities of second-stage juveniles (J2s) ranged from 300 to 350 in 100g soil layer of 10-20 cm. Nematodes were collected from root samples (n = 15) and were found in all of the diseased plant samples. Morphological and molecular analysis were conducted using females, males, and J2s. The perineal patterns of females (n = 20) showed a high dorsal arch, and with wavy striae, which mostly lacking obvious lateral lines. Morphological measurements of adult females (n = 20) include body length (BL) = 668.99 ± 24.56 (487.57-897.84) μm, body width (BW) = 433.73 ±12.84 (343.71-551.61) μm, stylet length = 15.64 ± 1.45 (10.86-28.26) μm, dorsal pharyngeal gland orifice to stylet base (DGO) = 2.57 ± 0.20 (1.41-3.68) μm, vulval slit length = 20.44 ± 0.91 (16.00-24.22) μm, and vulval slit to anus distance = 18.05 ± 1.06 (14.58-24.90) μm. The males showed a trapezoidal labial region, with a high head cap and concaved at the center of the top end in lateral view; and the stylet knobs were prominent, usually demarcated from the shaft. The morphological characters of males (n = 7) were as follows: BL = 1124.56 ± 53.97 (998.37-1336.52) μm, BW = 33.60 ± 0.79 (30.21-36.52) μm, stylet length = 23.63 ± 0.78 (20.14-26.37) μm, DGO = 3.04 ± 0.09 (2.69-3.38) μm, spicule length = 25.72 ± 0.57 (23.97-28.33) μm. The key morphometrics of J2s: BL = 439.13 ± 6.52 (398.32-481.33) μm, BW = 15.14 ± 0.26 (13.91-16.66) μm, stylet length = 13.44 ± 0.29 (10.96-14.60) μm, DGO = 2.13 ± 0.18 (1.22-3.10) μm, tail length = 57.46 ± 4.89 (38.85-101.33) μm, hyaline tail terminus = 16.93 ± 0.97 (11.45-22.54) μm. The morphological features of the females, males, and J2s match the original description of Meloidogyne incognita (Eisenback and Hirschmann, 1981). Eleven individual females were transferred to eleven different tubes for DNA extraction and the species-specific primers Mi2F4/Mi1R1 (ATGAAGCTAAGACTTTGGGCT/TCCCGCTACACCCTCAACTTC) were used for the identification of M. incognita (Kiewnick et al. 2013). A 300 bp target fragment was amplified by the primer pairs, confirming the RKNs collected from daylily plants were M. incognita. To confirm the result of species identification, the NADH dehydrogenase subunit 5 (nad5) from the mitochondrial DNA region was amplified using primers NAD5-F/R (TATTTTTTGTTTGAGATATATTAG/CGTGAATCTTGATTTTCCATTTTT) (Janssen et al. 2016). A fragment of 611 bp was obtained and the sequence (GenBank Accession No.OP115729) was 100% identical to the known sequence of M. incognita (GenBank Accession No. MT683461). The ITS region was amplified using the primers rDNA-F/R (TTGATTACGTCCCTGCCCTTT/TTTCACTCGCCGTTACTAAGG) (Vrain et al. 1992). The sequences from the ITS region were 768 bp (GenBank Accession No. OP095037) and showed 100% identical to the known sequence of M. incognita (GenBank Accession No. MH113856). An infection test was conducted in greenhouse conditions. Eighteen 5-weeks-old healthy daylily seedlings (cv. Shayuan) were individually cultured in 9 L pots filled with autoclaved-soil and each plant was inoculated with 3,000 J2s. Six non-inoculated daylily plants served as negative controls. After 60 days, all of the inoculated plant roots showed galling symptoms which were similar to those observed in the field, the nematodes were extracted from roots and were identified as M. incognita with the sequence-specificprimers Mi2F4/Mi1R1. No obvious symptoms were observed on control plants. An average of 9635 J2s were recovered from inoculated plants, (reproductive factor = 3.21), which confirmed the pathogenicity of M. incognita on daylily. Although it was reported that daylily was a host of M. incognita in Florida (Inserra et al. 1995), to our knowledge, this is the first evidence that M. incognita naturally infecting daylily in China. This root-knot disease leads to the yield reduction of daylily and may cause serious economic losses, so further studies should focus on the occurrence and effective control of this disease.

Genome-wide identification and expression analysis of the SWEET gene family in daylily (Hemerocallis fulva) and functional analysis of HfSWEET17 in response to cold stress

BACKGROUND

The Sugars Will Eventually be Exported Transporters (SWEETs) are a newly discovered family of sugar transporters whose members exist in a variety of organisms and are highly conserved. SWEETs have been reported to be involved in the growth and development of many plants, but little is known about SWEETs in daylily (Hemerocallis fulva), an important perennial ornamental flower.

RESULTS

In this study, 19 daylily SWEETs were identified and named based on their homologous genes in Arabidopsis and rice. Phylogenetic analysis classified these HfSWEETs into four clades (Clades I to IV). The conserved motifs and gene structures showed that the HfSWEETs were very conservative during evolution. Chromosomal localization and synteny analysis found that HfSWEETs were unevenly distributed on 11 chromosomes, and there were five pairs of segmentally duplicated events and one pair of tandem duplication events. The expression patterns of the 19 HfSWEETs showed that the expression patterns of most HfSWEETs in different tissues were related to corresponding clades, and most HfSWEETs were up-regulated under low temperatures. Furthermore, HfSWEET17 was overexpressed in tobacco, and the cold resistance of transgenic plants was much higher than that of wild-type tobacco.

CONCLUSION

This study identified the SWEET gene family in daylily at the genome-wide level. Most of the 19 HfSWEETs were expressed differently in different tissues and under low temperatures. Overexpression further suggests that HfSWEET17 participates in daylily low-temperature response. The results of this study provide a basis for further functional analysis of the SWEET family in daylily.

Daylily protein constituents of the pollen and stigma a proteomics approach

This study was aimed at the identification and quantification of the protein components of the pollen grains in parallel with the distal stigmatic tissue of tetraploid cultivars. Proteomes were analyzed using iTRAQ 4plex labeling, peptides separation by online RP-nano-LC and analysis by ESI-MS/MS. Protein identification and quantification were made using the Asparagales database as a reference. A total of 524,037 MS/MS spectra were produced from pollen and stigma samples. From these, a total of 8368 peptides wereidentified corresponding to 994 unique peptides and 432 protein groups. Among them, 128 differentially expressed proteins were retained for further analysis. In absence of the daylily genome availability, we exploited numerous databases and bioinformatics resources to exploring the putative biological functions of these proteins. The profile of differentially expressed proteins suggests an important representation of functions associated to the signalling and response against endogenous and environmental stresses, including several enzymes implicated in the biosynthesis of antibiotics. The abundance in stigma of several structural proteins of the ribosomal sub-units as well as of the core histones suggest that the translation processes and the regulation of gene expression in stigma is a more active mechanism than in pollen. In addition, pollen prioritizes the synthesis of fructose and glucose as opposed to sucrose in stigma as a source of energy. Finally, the modulated proteins in Hemerocallis point to several pathways that give potential clues concerning the molecular mechanisms underlying the functions of the pollen and the stigmatic fluid in daylily reproduction.

The Antidepressant-like Effect of Ethanol Extract of Daylily Flowers ( Jīn Zhēn Huā) in Rats

According to the prediction of the 2008 World Health Organization (WHO) report, depression will be the highest burden disease by the year 2030. Daylily flower ( Jīn Zhēn Huā ; the flower of Hemerocallis fulva) is traditionally used for soothing in Chinese dietary therapy. The major flavonoid of daylily flowers, rutin, is also characterized to be an antidepressant. In this study, we investigated the antidepressant effects of ethanol extract of daylily flowers (DFEtoH) and rutin by forced swimming test (FST) and neurotransmitter metabolism of brain regions (frontal cortex, hippocampus, striatum, and amygdala). Results show that either short- or long-term tests, the extract and rutin significantly reduce the immobility time and increased swimming time of FST, which are compared with the vehicle (P < 0.05). The extract and rutin also increase the serotonin, norepinephrine, and dopamine concentration of these brain regions (P < 0.05). In long-term tests, the daylily flowers extract markedly increased serotonin concentration and reduced serotonin turnover rate in these brain regions but not frontal cortex. In conclusion, present data illustrated that DFEtoH does have antidepressant-like effects possibly via the regulation of serotonergic system. Moreover, rutin might be playing a very important role in the antidepressant-like effects of DFEtoH.